 
   If you were to remove any call to `f` this test would fail with a verify error (`f` not invoked enough).
 
-  ## Exercise 3
+  ### Exercise 3
 
   Copy the following code to the top of your testing file:
 

  The `optional-regex` will match the message of the exception. The optional-predicate is a function that will be given
  the exception instance, and can make additional assertions about the exception.

  ## Exercise 2

  Create an additonal spec (in the same file as before) that uses the `=fn=>` arrow to check that an expression results
  in an even value.

  ### Mocking

  The mocking system does a lot in a very small space. It can be invoked via the `provided` or `when-mocking` macro.
  The former requires a string and adds an outline section. The latter does not change the outline output.


  Add `:remote true` to your return value from `a-mutation`. The test should now pass.

  #### Exercise 9

  Test a mutations that modifies the ui-tx.

  As you probably already know, it is possible to modify the mutation sent to the server by giving an AST
  as the value of `:remote` instead of `true`. Add a parameter to the transaction by modifying the mutation to:

  ```
   (defmethod m/mutate 'a-mutation [{:keys [state ast] :as env} k params]
